Is this the only toner I need for color printing?

No, this is only the black toner cartridge. There are 3 other toner cartridges used for color, those are the cyan, yellow, and magenta cartridges. You will most likely run out of the black toner long before you run out of the others though.

Which printers are compatible with the Canon 118 Toner Cartridge?

The Canon 118 Toner Cartridge is compatible with the Canon imageCLASS MF8350CDN printer, as well as the imageCLASS MF8580Cdw, MF726Cdw, and MBP7660Cdn models.